Shedding light on the effective fluorophore structure of high fluorescence quantum yield carbon nanodots

Journal article
(Original article)


Publication Details

Author(s): Wang W, Wang B, Embrechts H, Damm C, Cadranel A, Strauß V, Distaso M, Hinterberger V, Guldi DM, Peukert W
Journal: RSC Advances
Publisher: Royal Society of Chemistry
Publication year: 2017
Volume: 7
Journal issue: 40
Pages range: 24771-24780
ISSN: 2046-2069


Abstract

Carbon nanodots (CD) have great potential for imaging and sensing applications, due to their unique luminescence properties in combination with their low toxicity. Although CDs are currently the subject of intensive research activity, the exact structure of their effective fluorophore species has to be clarified because it can depend on the starting materials and reaction conditions. Most importantly, the limited photostability of some CDs presents an impediment to the much-needed breakthroughs required in the field. In this work, the photobleaching of CDs synthesized hydrothermally from citric acid and urea undervarious conditions is studied in detail. By visualizing changes in the absorption and fluorescence properties of CDs over time upon exposure to UV-light by means of in situ spectroscopic probes, we demonstrate a trade-off between high initial quantum yield and photostability. We found that the CDs consist of low-molecular weight fluorophores bound to \textgreekp-conjugated domains (carbon core). In the case of CDs synthesized at higher reaction temperatures and/or for longer reaction times, lower initial quantum yields and higher photostability originate from partial conversion of the low-molecular weight fluorophores to \textgreekp-conjugated domains during synthesis. Thus, the remaining surface bound fluorophores are bound to larger \textgreekp-conjugated domains, which, in turn, enable dissipation of absorbed UV-energy and protection against photochemical damage. Reference experiments were performed with citrazinic acid -- a pyridone-based structure -- using ultrafast time-resolved spectroscopy, steady-state spectroscopy, and theoretical DFT simulations. We conclude that pyridone-like structures are most likely responsible for both the high quantum yields and the photobleaching of CDs.


FAU Authors / FAU Editors

Cadranel, Alejandro Dr.
Sonderforschungsbereich 953/2 Synthetische Kohlenstoffallotrope
Damm, Cornelia Dr.
Lehrstuhl für Feststoff- und Grenzflächenverfahrenstechnik
Distaso, Monica Dr.
Lehrstuhl für Feststoff- und Grenzflächenverfahrenstechnik
Embrechts, Heidemarie
Lehrstuhl für Feststoff- und Grenzflächenverfahrenstechnik
Guldi, Dirk Michael Prof. Dr.
Lehrstuhl für Physikalische Chemie I
Michaud, Vanessa
Lehrstuhl für Feststoff- und Grenzflächenverfahrenstechnik
Peukert, Wolfgang Prof. Dr.-Ing.
Lehrstuhl für Feststoff- und Grenzflächenverfahrenstechnik
Strauß, Volker
Interdisziplinäres Zentrum für Molekulare Materialien
Wang, Wenshuo
Lehrstuhl für Feststoff- und Grenzflächenverfahrenstechnik
Wang, Bingzhe
Lehrstuhl für Physikalische Chemie I


Additional Organisation
Exzellenz-Cluster Engineering of Advanced Materials


Research Fields

B Nanoelectronic Materials
Exzellenz-Cluster Engineering of Advanced Materials
A1 Functional Particle Systems
Exzellenz-Cluster Engineering of Advanced Materials


How to cite

APA:
Wang, W., Wang, B., Embrechts, H., Damm, C., Cadranel, A., Strauß, V.,... Peukert, W. (2017). Shedding light on the effective fluorophore structure of high fluorescence quantum yield carbon nanodots. RSC Advances, 7(40), 24771-24780. https://dx.doi.org/10.1039/c7ra04421f

MLA:
Wang, Wenshuo, et al. "Shedding light on the effective fluorophore structure of high fluorescence quantum yield carbon nanodots." RSC Advances 7.40 (2017): 24771-24780.

BibTeX: 

Last updated on 2019-14-03 at 11:42